From a story on lithub.com headlined “The Craft of Writing”:

Abraham Verghese on plots and plotting.

Many of the writers I greatly admire, like John Irving and Richard Ford, have said that they invest a great deal of time in plotting out their stories before they embark. Irving knows the first and last line of his book and the last line of each chapter before he starts the first draft. He once said to me that a writer must know what’s happening — otherwise how can they decide what information to hold back from the reader and when to reveal it? If you’re making it up as you go along, he said to me gently, then you aren’t a writer but an ordinary liar! But even he admits that things change once he starts writing. And he has always said that the real art is in revision. Still, I think what makes him such a great storyteller is that he knows pretty much everything before he begins.